Various gate systems are known in the art pertaining to movable dams and spillway gravity dams. Generally speaking, a gate may be positioned between two abutments constructed along the river bank or reservoir. The gate may then be moved between a practically vertical position and a substantially horizontal position to withhold or release water within the dam.
Movable gate elements of this type comprise a wicket panel or wall that is pivotally mounted to the floor or body of the dam and supported in varying upright positions by means of a prop pivotally attached at one end to the gate and at its other end to a stop catch secured to the dam floor.
Such a gate system is described in U.S. Pat. No. 4,352,592 (Aubert) which is incorporated herein by reference. The Aubert gate system comprises a wicket panel or wall pivotally mounted at one end to the dam floor, so as to allow a range of movement between a substantially vertical position and a collapsed horizontal position. The wicket panel further includes an elongated prop or support shaft which is pivotally attached at its upper end to the rear of the wicket panel thereby selectively supporting the panel between an upright and a collapsed position. The lower end or foot of the prop is supported in one of a series of stop catches projecting from a slide or hurter mounted to the dam floor. Depending upon whether the foot of the prop is engaged against one stop catch or another, the wicket wall will take up a corresponding position of pre-determined inclination. In addition, a pivotally mounted jack or hydraulic cylinder is located downstream with respect to the wicket and serves to raise or lower the wicket wall when repositioning is so desired.
A problem frequently encountered with such gate systems is damage to the gate and its associated hardware after accidental barge impact against the wicket gate. If a barge or other vessel situated in the water and near the gate repeatedly impacts or bumps into the gate, the prop and/or wicket is easily damaged. This is generally the case because of the rigid support rendered by the prop when the gate is positioned in an upright manner. Repeated impact upon the wicket and its associated components often results in failure and jamming of the various pivot points with a consequential reduction in reliability of operation.
Thus, a need has existed in the art for minimizing damage to the gate system components in the event of inadvertent impact against the wicket gate during operation.